Spark-advancer.



F. CONRAD.

SPARK ADVANCER.

APPLICATION FILED NOV. 16. 191 1.

Patented Feb. 15, 1916.

Fig. 3.

INVENTOR M ESSES:

ATTORNEY UNITED STATES PATENT OFFICE.

FRANK CONRAD, 0F SWISSVALE, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE ELECTRIC'AND MANUFACTURING COMPANY, A CORPORATION OF PENNSYL- VANIA.

SPARK-ADVANGER.

Specification of Letters Patent.

Patented Feb. 15, 1916.

Application filed November 16, 1911. Serial No. 660,652.

To all whom it may concern:

Be it known that I, FRANK CONRAD, a citizen of the United States, and a resident of Swissvale, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Spark-Advancers, of which the following is a specification.

My invention relates to interrupters and spark advancers for use with internal combustion engines, and it has for its object to provide a device whereby the spark will be automatically advanced with respect to the position of the engine piston in accordance with variations of the engine speed, and also whereby the period of engagement of the interrupter contact members will be automatically maintained substantially uniform with changes of the engine speed.

My invention is illustrated in the accompanying drawings, Figure 1 of which is a side and sectional view of a combined interrupter and spark advancer constructed in accordance therewith. Fig. 2 is an end and sectional view of the device of Fig. 1, and Fig. 3 is an enlarged end view of the rotating parts of the device.

My invention is adapted to be employed in connection with a magneto or generator of current for ignition or other purposes, or directly in connection with the engine, and it is mounted at one end of a shaft 1 constituting a part of any of said machines. Two pins or posts 2 and 3 are screwed into holes in the end of the shaft 1 at opposite sides of its axis and parallel thereto to serve as pivots for two centrifugally actuated levers 4 and 5 of substantially semi-cylindrical outer contour and having central shallow channels in their circumferential faces which form ribs adjacent to their edges. The abutting faces 4 and 5 of the ends of levers 4 and 5 are radial for approximately one-fourth of the diameters of their cylindrical portions and the remaining or inner portions of the abutting faces are of irregular contour, being severally shaped to provide laterally extending arms 6 and 7 and recesses 8 and 9 for the reception of the opposing arms. The engaging faces of the arms and recesses are of such shape that the levers are caused to move simultaneously and correspondingly under the action of centrifugal force. Thus, movement of the lever 4 upon its pivot 2 causes the arm 6 to press against the face of the recess in the lever 5 to effect a corresponding movement of the said lever, and movement of the lever 5 upon its pivot 3 causes the arm 7 to press against the face of the recess in the lever 4 to effect a corresponding movement of the said lever.

Diametrically opposite ends of the levers 4 and 5 are slotted for the reception of rollers 10 and 11 that protrude from the slots slightly beyond the cylindrical faces of the levers, the said rollers being mounted upon pins 10 and 11 that extend through the levers and project from the outer end faces thereof. The other ends of the levers 4 and 5 are solid and constitute weights upon which centrifugal forces act to move the levers, and the disposition of the rollers with respect to the pivot or fulcrum points of the levers is such that they are moved both angularly forward and radially outward as the Weighted ends of the levers are moved outwardly by centrifugal force. In this connection, it will be noted that the cylindrical faces of the levers 4 and 5 are not concentric with the axes about which they revolve, thus permitting of movements of the levers within the limited space allowed.

The levers 4 and 5 are normally maintained in the positions shown by means of springs 12. that are supported by arms 13 carried by a block 14 that is mounted upon the outer ends of the-pins or posts 2 and 3, the said block being secured upon the said pins by means of a cotter pin'15 that extends through transverse apertures in the ends of the pins. The free ends of the springs 12 bear against the inner faces of the projecting ends of the bearing pins 10 and 11, thereby serving to resiliently oppose movements of the levers 4 and 5 by centrifugal action.

The stationary parts of the device are carried by a base or bracket 17 that is suitably secured to the frame or other stationary part of the magneto, generator or engine, and is provided with a cylindrical sleeve portion 18 surrounding the levers 4 and 5,

the lower portion of the said sleeve being omitted or cut away for a distance of approximately 90 degrees. The sleeve 18 serves as a bearing for another sleeve 19 that closely fits the same and the lower portion of which is also omitted or cut away, the said sleeve constituting a part of, and a support for, a shell or frame 20 having lugs 21 for the attachment of means whereby the same may be rotated manually by the driver or operator.

Within the. frame 20, and pivotally supported thereby, is a bell crank lever 22 one end 22 of which projects through the spaces left by the omitted or cut away portions of the sleeves 18 and 19 and is located in the path of movement of the rollers 10 and 11. The face of the said lever that is adapted to be engaged by the said rollers has a curvature that is slightly eccentric with respect to the axis of the shaft 1; that is, to the path of rotation of the rollers 10 and 11. The same end of the lever is provided upon its rear with a hook 23 that is adapted to engage a pin 24 constituting a part of a bridging member 25 having contact faces that are adapted to engage corresponding stationary contact members 26 and 27 The lever 22 is normally maintained in the position shown by means of a spring 28 that is secured thereto intermediate its ends, one end bearing against a stationary post 29, While the'other end bears against the pin 24: that constitutes part of the bridging member 25 and resiliently maintains the same in engagement with the hook 23. The post 29 also serves as a stop against which one end of the lever 22 normally bears. The hook 23, the pin 2& and the spring 28 constitutes a resilient lost-motion connection between the lever 22 and the bridging member 25, so that the lever 22 may continue its move ment after the bridging member 25 engages the contact terminals 26 and 27. The contact terminals 26 and 27 are screwed into supporting members 31 and 32, respectively, that are secured to the shell or frame 20, and the latter of which is electrically connected to the said frame while the former is insulated from it and connected to a binding post 33. The contact terminal 27 is preferably one of the grounded connections of the ignition system.

Tn the operation of the device, the weighted ends of the levers 4 and 5 are moved outwardly by centrifugal force,

against the action of the springs 12, in proportion to the speed at which they are revolved, the. rollers 1'0 and 11 being thus moved around the pins 2 and 3, respectively,

as centers. The relation of the parts is such that, as the arms 4 and 5 are actuated by centrifugal force, the rollers 10 and 11 are advanced from their initial or normal positions in the direction of revolution, being thus caused to engage the eccentrically curved end 22 of the bell crank lever 22 sooner with respect to the corresponding positions of the engine pistons for the higher engine speeds than for the lower. The resultis that the spark occurs in the engine cylinders sooner with respect to the positions of the pistons than would otherwise be the case. Furthermore, because of the pivoting of the levers 4 and 5 eccentrically with respect to their axis of revolution and of the peculiar relations of the parts, the rollers 10 and 11 are not only advanced by centrifugal action upon the levers, but they are also moved radially outward as the speed of the engine increases. Then, since the face of the lever 22 that is adapted to be engaged by the rollers 10 and 11 is eccentically curved, the rollers 10 and 11 will not only engage the said face sooner with the higher speeds, but will also engage it during greater portions of their angular movements at the higher speeds. The arrangement is such that, as the speed of the engine increases, the angular distance of engagement between the rollers and the lever Will correspondingly increase, thereby maintaining the periods of engagement of the contact members of the interrupter substantially uniform with changes of speed. The importance of this feature will be appreciated when it is understood that the interrupter contact members should engage a certain period of time for the most effective production of the spark, and that, if this period is exceeded, more than the necessary amount of current will be utilized, whereas, if it is diminished, the spark is likely to be "less effective and reliable. With the present device, the period of engagement of the interrupter contact members may be adjusted for the most effective operation at slow speeds, and this period will be automatically maintained substantially uniform at all engine speeds, by reason of the construction and operation of the device as above set forth. In the use of the device, a manual adjustment will preferably be made, once for all, for the most desirable and effective advance or lead of the spark, permitting the device to thereafter operate automatically to maintain a suitable advance, though,

if desired, the adjustment of the frame 20 may also be under the control of the operator or driver.

I claim as my invention:

, 1. A spark advancer comprising a pair of contact members, a rotatable member, means for controlling the engagement and disengagement of said contact members at points varying in angular relation with respect to said rotatable member according to the speed of said rotatable member, and means comprising a concave surface connected to one of the contact members for making the period of engagement of said contact members substantially uniform at varying speeds.

2. A spark advancer comprising a revoluble member that is adjustable both radially and circumferentially with respect to its axis and path of revolution, and a switch member actuated thereby and having a concave face that is eccentric with respect to the axis of revolution of the revoluble member and is interposed in the path of movement thereof, whereby the extent of the said face that is engaged by said revoluble member varies in accordance with the speed of said revoluble member.

3. A spark advancer comprising a revoluble member that is adjustable both radially and circumferentially with respect to its axis and path of revolution in accordance with its speed of revolution, a switch member that is interposed in the path of movement of, and is actuated by, the said member, and a contact member having a resilient lostmotion connection with the switch member.

4. A spark advancer comprising a revoluble member that is adjustable both radially and circumferentially with respect to its axis and path of revolution, a switch member actuated thereby and having a face that is eccentric with respect to the axis of revolution of the revoluble member and is interposed in the path of movement thereof, and a contact member having a resilient lost-motion connection with the switch member.

5. A spark advancer comprising a rotatable member, a switch member, means on said rotatable member for actuating said switch member at points varying in angular relation with respect to said rotatable member according to the speed of said rotatable member, and means for making the periods of actuation of said switch member substantially constant at varying speeds, said means comprising a concave surface on said switch member.

6. A spark advancer comprising a rotatable member, a centrifugally actuated arm eccentrically pivoted thereon, one end of which is adjustable both radially and circumferentially with respect to said member, and a switch member having a concave surface eccentric to the axis of said rotatable member thatiis interposed in the path of movement of, and is'periodically engaged by, the said adjustable end of the arm, whereby the periods of engagement are substantially uniform at varying speeds.

7. A spark advancer comprising a rotatable member, centrifugally actuated arms eccentrically pivoted to said member and having engaging cam faces, whereby they are'caused to move simultaneously and correspondingly, and a switch member actuated by the said arms.

8. A spark advancer comprising a rotatable 'member, centrifugally actuated arms eccentrically pivoted to said member and having engaging cam faces, whereby they are caused to move simultaneously and correspondingly, rollers carried by said arms, means for resiliently opposing centrifugal action upon the said arms, and a switch member actuated by the said rollers.

9. A spark advancer comprising a rotatable member, centrifugally actuated arms eccentrically pivoted to said member and having engaging cam faces, whereby they are caused to move simultaneously and correspondingly, and a switch member having a face that is eccentric with respect to the axis of rotation of the rotatable member and is interposed in the path of movement of the said arms.

10. A spark advancer comprising a rotatable member, centrifugally actuated arms eccentrically pivoted to said member and having engaging cam faces, whereby they are caused to move simultaneously and correspondingly, a switch member having a face that is eccentric with respect to the axis of rotation of the rotatable member, and is interposed in the path of movement of the said arms, and a contact member having a resilient lostmotion connection to the switch member.

11. A spark advancer comprising a rotatable member, centrifugally actuated arms eccentrically pivoted to said member and having corresponding engaging cam faces to produce simultaneous and corresponding movements of said arms, and a switch member having a face eccentric to the axis of the rotatable member and which is interposed in the path of the said arms.

12. A spark advancer comprising a centrifugally actuated revoluble member, and a switch member actuated by said revoluble member and having an engaging surface so shaped that the periods of actuation by said revoluble member are substantially uniform at varying speeds.

13. A spark advancer comprising a rotatable member, arms carried by said member which advance angularly and radially with respect to said member as the speed is increased, and a switch member interposed in the path of said arms and having means for making the periods of actuation by said arms substantially constant atvarying speeds.

14. A spark advancer comprising a rotatable member, an arm on said member automatically actuated by centrifugal force to advance angularly and radially with respect to said member and a switch member actuated by saidarm and having a surface for engaging said arm so shaped that the periods of actuation are substantially constant for various positions of said arm.

15. A spark advancer, comprising a rotatable member, an arm carried by said member and adapted to be advanced by centrif-- ugal force, angillarly and radially with respect to said member, and a switch member actuated by said arm and having means comprising a curved surface for causing the said 5 arm to engage an increased portion of said surface as the speed is increased. In testimony whereof, I have hereunto subscribed my name this 14th day of Nov.,

FRANK CONRAD.

Witnesses:

WILLIAM BRADSHAW, B. B. HINES. 

